Answer:
[tex]F = 76.05\,N[/tex]
Explanation:
The phenomenon can be described and analyzed by means of the Principle of Momentum Conservation and the Impact Theorem:
[tex](6.5\times 10^{-3}\,kg)\cdot (650\,\frac{bullets}{min} )\cdot (\frac{1\,min}{60\,s} )\cdot (540\,\frac{m}{s} ) - F = (6.5\times 10^{-3}\,kg)\cdot (650\,\frac{bullets}{min} )\cdot (\frac{1\,min}{60\,s} )\cdot (-540\,\frac{m}{s} )[/tex]
The magnitude of the average force on Superman's chest is:
[tex]F = 76.05\,N[/tex]